[Bug libstdc++/121348] `vector::resize(n, value)` incorrectly requires the element type to be assignable

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121348

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
https://eel.is/c++draft/vector.capacity

Preconditions: T is Cpp17CopyInsertable into vector.

https://eel.is/c++draft/container.alloc.reqmts#def:Cpp17CopyInsertable_into_X

T is Cpp17CopyInsertable into X means that, in addition to T being
Cpp17MoveInsertable into X, the following expression is well-formed:
allocator_traits<A>::construct(m, p, v)
and its evaluation causes the following postcondition to hold: The value of v
is unchanged and is equivalent to *p.


Looks like there was a change between C++14 and C++17 here though.

Because in C++14 (via issue 2033; https://cplusplus.github.io/LWG/issue2033), 
It was "Requires: T shall be MoveInsertable into *this and CopyInsertable into
*this."